In surgical operations it is often necessary to insert tubular instruments into small body cavities in order to manipulate, modify or resect pathological tissues which may include, for example, lesions, polyps, cysts, fibroids, lymph nodes, choroid tissues, and other abnormal tissue growths, to name a few. When an instrument is introduced into a body cavity during an operative procedure, in some cases, undesired tissue injury can be expected. However, the risk of significant undesired tissue injury increases as the ability to view what is happening with the instrument decreases. In other words, there is significantly greater risk of injury when an instrument must be inserted and used “blindly” (i.e. only by feel) than there is when the insertion path and area of use can be fully viewed.
While, in some cases, a potential undesirable injury such as a laceration or perforation may not present a significant risk so as to require remedial action (i.e. it will heal on its own), in other cases, such as an injury occurring in an organ like the uterus, intestine or bowel, a laceration or perforation can be life threatening—in the former organ due to excessive bleeding and, in the latter organs, by potentially causing peritonitis.
In general, the evolution of endoscopic surgical technology has vastly reduced average morbidities for many operative procedures, and methods for resection of pathological tissue have improved over time. However, despite these advances organ lacerations and perforations still occur. Moreover, currently available technologies are designed to promote freedom to the surgeon through a largely exposed cutting member and thus increase, rather than decrease the possibility of causing undesirable tissue injury. In addition, current resectoscopic instruments are generally complicated, balky, and often require multi-component reconfiguration during use.
When tissue is removed during a surgical procedure, capture of the resected tissue is necessary for surgical pathology testing. Unfortunately, in certain organs, efficient removal of pathological tissue from an operative site remains problematic. For example, with respect to removal of pathological tissue from the uterus, the present practice for hysteroscopy follows a process beset by multiple task interruptions. The process begins with the trays containing the hysteroscope and resectosocopic instruments opened onto the sterile field for assembly into one of two separate operational modes.
First, a diagnostic sleeve is usually set up for use with the hysteroscope to allow the surgeon entry into the uterus. The surgeon performs an initial diagnostic hysteroscopy to identify the tissue(s) to be removed and their location.
After the diagnostic hysteroscopy, the setup is withdrawn and disassembled with the scope extracted from the assembly. A separate resectoscopic instrument is then assembled involving placement and alignment of an electrode upon the scope including electrode insertion and fixation into a small hole. A bridge piece is then inserted onto the assembly along with a new sleeve assembly. A fluid pressure regulator is attached to the inflow port of the instrument and a power source is connected.
Now the resectoscopic instrument is carefully entered into the uterus after further dilation of the cervix to accommodate its larger diameter and pipe-like tip. Here the surgeon must be very careful to avoid perforation of the uterus by the cutting tendency of the resectoscope itself. In addition, the surgeon must avoid accumulation of endometrium tissues within the tip assembly since those tissues will obscure the view. If the view becomes too obscured, removal and cleaning prior to reinsertion is required.
Once the resectoscope is within the uterine cavity, the surgeon employs careful adjustment between the inflow and outflow valves to infuse fluid into the uterus to open it and to remove fluid within the uterus which has become tainted with blood from the abrasion of tissues that is inherent with the insertion. Only when a balance between the inflow and outflow is obtained such that where the uterus is opened and inflated and the view is clear can the actual resection work begin. A typical balanced flow rate is around 10 cc/min.
The resectoscope is then maneuvered into position near the tissue to be resected and, with a clear view for resection, the loop electrode is extended beyond the distal end of the resectoscope. The loop is then placed near the tissue to be resected, the electroloop is activated, and the loop is drawn back toward the resectoscope itself causing the loop to simultaneously cut off a piece of the tissue and cauterize the wound in the tissue left behind. The process of extension and withdrawal would then be repeated until the full extent of the identified tissue is removed. However, the process is rarely that straightforward. More typically, the resection process is repeatedly interrupted by clogging of the tip assembly by tissue, or by sticking of the tissue to the loop itself. When this happens, removal, cleaning and reinsertion of the entire assembly may be necessary.
In addition, as noted above, each tissue piece must be captured for surgical pathology. With the present devices, the resectoscope can be employed to intentionally snare and remove each tissue piece, but this requires removal of the entire assembly to remove the individual tissue piece, re-insertion of the resectoscope, abatement of any new bleeding, re-attaining of the proper the balance between fluid infusion and removal to gain an adequate view, and only then, working on the next small tissue piece to be resected. Alternatively, if the resectoscope is not used, a tissue forcep may be blindly substituted for the resectoscope in order to attempt removal of the tissue. In either case, diagnostically important pieces of tissue may be lost in the effluvium of uterine deflation, or dropped and lost in the handoff from surgeon to technician.
Still further, if cautery needs exceed the ability of the resection loop during the process, the entire mechanism must be withdrawn and disassembled to remove the electro-loop and substitute a roller-ball electrode. Then, re-assembly, and subsequent re-insertion and fluid flow re-balancing are required in order to accomplish this phase of cautery. Then, if further resection is still necessary or desired after the cautery, the removal, reconfiguration, re-balancing, etc. process must be repeated.
Once the procedure is finally complete from the surgeons perspective, the process must continue for purposes of surgical pathology. In that regard, the instrument is handed off to a technician who disassembles it and removes any tissue pieces that have attached to any of the multiple sleeves, auxiliary instruments, obturators, stop-cocks, scope, bridge pieces, holes and grooves. In addition, the electroloop is removed and disposed of into the sharps container.
Since the instruments are all reused, after disassembly, the multiple elements must be transported to the area where final cleaning is done before sterilization and re-packaging. Thereafter, at some point a transport is required to return the now cleaned, sterilized and repacked unassembled kit and tray to the peri-operative supply area for its next use.
Some newer systems employ variations on the same basic free-flow hysteroscopic resectoscope in which an auxiliary instrument can be inserted through the hysteroscope for the purpose of tissue capture and removal.
In some variants tissue morcellation is employed which requires time. Other variants require a complex opening mechanism to obliquely pass a small auxiliary tissue cutting and capture instrument to thereby allow for tissue capture and removal. These geometric changes increase the size of the instrument and thus limit the use of the instrument to areas of the body or body cavity that can accommodate the size change and/or overall increased size. These methods also involve optically guided capture and manipulation of tissue morsels in order to accomplish their export with or without further morcellation. Most of these variant methods require interruption of cutting to allow for removal of resected tissue. In addition, none of these variant techniques meaningfully reduce organ perforation risk. Still further, to avoid removal of an excessive amount of tissue, resection is typically done in a series of passes, with every pass involving a “guess” as to the required (and actual) depth of cut, particularly because gasses from tissue destruction and heat largely obscure the cutting loop from precise view during the actual cutting. As a result, surgeons are forced to weigh and ultimately succumb to the trade-off between over-removal with its attendant risk of organ perforation or under-removal with the prospect that a repeat procedure may, at some point, be necessary.
Removal of pathological tissue from other organs routinely involves, to varying degrees, multiple steps of a somewhat analogous nature (i.e. multiple insertions/removals and issues relating to capture of resected pathological tissue) and thus analogous or similar problems exist with those operations as well.
As will be appreciated, the above example procedure to remove pathological tissue from the uterus is time consuming and typically takes between 30 and 60 minutes to perform. With operating room costs exceeding several thousand dollars an hour, this can lead to substantial costs for a patient as well as the hospital in which the resection is performed.
Thus, there is a need for a surgical device that does not suffer from problems attendant with existing devices.
In addition, there is a need for a surgical device that can reduce the time required to perform a resection procedure and thereby, the costs associated with doing so.